Omar Eljumaily <omar2(at)omnicode(dot)com> writes:
> I want to tabulate time data on a weekly basis, but my data is entered
> on a daily basis.
Something involving GROUP BY date_trunc('week', _date) might work for
you, if your definition of week boundaries matches date_trunc's.
If not, you could probably make a custom function that breaks at the
boundaries you want.
regards, tom lane